It is always desirable to detect diseases early in their progress. Early detection enables early treatment which has generally been proven to yield a higher success rate in treating various diseases. Recently, it has been discovered that analyzing peoples' eyes, and in particular the lenses of the eyes, can yield indications of various types of diseases. For example, measurements taken of light scattering within the eye has been shown to provide useful diagnostic information to detect and monitor the progress of diseases such as Alzheimer Disease [AD]. This disease in particular has recently been shown to cause changes in the supra-nuclear region of the lens of the eye. Since this region is only a fraction of a millimeter thick, measurements of this region, to be useful, need to be very accurate in the information for the position of the measurement. This is especially true because the human eye is in almost constant motion even when a patient is fixating on an illuminated target.
It has been shown that the presence of or an increase in the amount of aggregate in the supranuclear and/or cortical lens regions of a test mammal's eye compared to a normal control value indicates that the test mammal is suffering from, or is at risk of, developing a neurodegenerative disease such as an amyloidogenic disorder. Amyloidogenic disorders include AD, Familial AD, Sporadic AD, Creutzfeld-Jakob disease, variant Creutzfeld-Jakob disease, spongiform encephalopathies, Prion diseases (including scrapie, bovine spongiform encephalopathy, and other veterinary prionopathies), Parkinson's disease, Huntington's disease (and trinucleotide repeat diseases), amyotrophic lateral sclerosis, Down's Syndrome (Trisomy 21), Pick's Disease (Frontotemporal Dementia), Lewy Body Disease, neurodegeneration with brain iron accumulation (Hallervorden-Spatz Disease), synucleinopathies (including Parkinson's disease, multiple system atrophy, dementia with Lewy Bodies, and others), neuronal intranuclear inclusion disease, tauopathies (including progressive supranuclear palsy, Pick's disease, corticobasal degeneration, hereditary frontotemporal dementia (with or without Parkinsonism), and Guam amyotrophic lateral sclerosis/parkinsonism dementia complex). These disorders may occur alone or in various combinations. Aggregate analysis is also useful to detect Transmissible Spongiform Encephalopathies (TSEs), which are prion-mediated diseases characterized by fatal spongiform neurodegeneration of the brain and are associated with severe and fatal neurological signs and symptoms. TSE prionopathies include Creutzfeld-Jacob Disease (CJD); new variant, Creutzfeld-Jacob Disease (nv-CJD); Gertsmann-Straussler-Scheinker syndrome; fatal familial insomnia; Kuru; Alpers Syndrome; Bovine Spongiform Encephalopathy (BSE); scrapie; and chronic wasting disease (CWD).